North Korea says it has successfully tested a new type of intercontinental ballistic missile that can reach the whole of continental US.
It claimed in a special announcement on state television that it had launched a Hwasong-15 missile early on Wednesday.
The test has prompted international condemnation.
The missile, which landed in Japanese waters, reached an altitude of 4,500km (2,800 miles) and flew 960km, according to South Korea's military.
Pyongyang said that the launch was personally signed off leader Kim Jong-un.
The missile test was the latest in a series of weapons tests that has raised tensions. Pyongyang last launched a ballistic missile in September, the same month it conducted its sixth nuclear test.
North Korea has continued to develop its nuclear and missile programme despite global condemnation and sanctions.
The UN Security Council is due to convene an emergency session to discuss the latest test.